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591.
Regional monitoring of lead and cadmium contamination in a tropical grazing land site,Thailand 总被引:1,自引:0,他引:1
Parkpian P Leong ST Laortanakul P Thunthaisong N 《Environmental monitoring and assessment》2003,85(2):157-173
An investigation was carried out to monitor Pb and Cd contamination in grazing land located near a highway. Environmental media at different distances fromhighway (soil, grass, water, cow's forage, fertilizer,manure and milk samples) were collected from three samplinglocations. Soil and grass were characterized by high metalmobility (soil with Pb: 5.25±0.71–14.59±1.17 mgkg-1, dry mass and Cd: 0.038–0.33±0.04 mg kg-1, dry mass and grass with Pb: 0.76±0.05–6.62±0.18 mg kg-1, dry mass and Cd: 0.17±0.01–0.73±0.09 mg kg-1, dry mass). One-way analysis of variane (ANOVA) was applied to find out the correlation between metal (total and bioavailable) concentrationsin the soil and the distance from roadside. In most cases, the finding showed that plants growing nearer to the highway are usually exposed to more heavy metal accumulations than those awayfrom the highway. In addition, a correlation was established between plant available metal concentrations and plant metaluptake concentrations.Analysis of fertilizer and manure showed considerable amountof metals (fertilizer with Pb: 1.53±0.06 mg kg-1 andCd: 0.038 mg kg-1 and manure with Pb: 2.55–3.34 mgkg-1 and Cd: 0.14–0.31 mg kg-1). Long termsimultaneous application of fertilizer and manure on thecommercial farm showed higher metal accumulation in the soiland plants than those of co-operative farm Considerableconcentrations of metals (Pb: 1.60–2.94 mg kg-1 andCd: 0.025–0.19 mg kg-1) were observed in fodder. The finding clearly demonstrated that there are seasonalvariation in total daily metal intake by individual cow (Pb:109.37 mg day-1 (dry), 273.47 mg day-1 (rainy) andCd: 2.02 mg day-1 (dry), 19.62 mg day-1 (rainy)).The provisional tolerable weekly intake of heavy metals incows is 390 g Pb and 28 g Cd per kg bodyweight in the rainy season and 156 g Pb and 2 gCd per kg body weight in the dry season. The levels of metals (Pb: 0.014 mg L-1 and Cd: not detectable) and bio-transferfactor (10-5–10-4) in raw milk were found to be well below the Codex Alimentarius Commissions Draft (1997). Ouranalysis revealed that improvements on farm management give significant reduction in elevated levels of Pb and Cdin soil and plants, and however leads to minimize the amountof Pb and Cd in consumed milk. 相似文献
592.
开拓有机高分子絮凝剂在炼厂污水处理中的应用 总被引:4,自引:0,他引:4
顾薇琼 《石油化工环境保护》1997,(2):35-38
通过有机高分子絮凝剂在炼厂污水处理中的应用试验,表明有机高分子絮凝剂各方面性能均优于单一的无机盐絮凝剂。开拓有机高分子絮凝剂在炼厂污水处理中的应用,是当前提高污水外排综合合格率的一个重要手段。 相似文献
593.
大治河有机污染源分析及防治对策 总被引:2,自引:0,他引:2
根据历年来大治河水质监测资料,分析了大治河水污染的特征是有机污染型。通过对大治河水源保护区域内的污染源调查,结果表明,有机污染中既有点污染源的贡献,但主要来源于非点污染源。后者的污染负荷是前者的54倍。因而提出了为改善和提高大治河水质的若干对策意见。 相似文献
594.
序列式活性污泥法稳定性研究 总被引:4,自引:0,他引:4
本文报道了对序列式活性污泥法稳定性的研究结果,研究表明,对于周期间的变浓度恒负荷、变浓度变负荷以及周期内变浓度变负荷冲击,该工艺均表现出良好的稳定性。 相似文献
595.
596.
将冷阱用于液样浓缩器(LSC)/色谱/质谱(GC/MS)装置中,可对饮用水中挥发性有机污染物进行快速定性、定量分析.此方法适用于对饮用水及天然水体中挥发性有机污染物的普查和监测. 相似文献
597.
有机废水两相厌氧消化工艺相分离问题的探讨 总被引:3,自引:0,他引:3
本文通过对厌氧微生物代谢机理和有关实验结果的分析,对两相厌氧消化工艺中的分相同题进行了深入探讨,澄清了产酸相和产甲烷相的概念,讨论了相分离的可行性和途径,并解释了一些试验中出现的问题。 相似文献
598.
疏水性有机物和有机酸碱溶解度的估算 总被引:1,自引:2,他引:1
本文从理论上建立了疏水性有机物和任意pH条件下有机酸碱溶解度的估算方法,并估算了不同类型有机物的溶解度,和实测值比较,结构和辛醇相近的有机物吻合较好;结构不同,则有一定的偏差,这是由于假设有机物在辛醇中的活度系物等于1所致。经校正后得到了较好的结果。 相似文献
599.
600.
Pathak H Bhatia A Prasad S Singh S Kumar S Jain MC Kumar U 《Environmental monitoring and assessment》2002,77(2):163-178
Nitrous oxide (N2O) accounts for 5%of the total enhanced greenhouse effect and responsiblefor the destruction of the stratospheric ozone. The rice-wheat cropping system occupying 26 million ha ofproductive land in Asia could be a major source ofN2O as most of the fertilizer N in this region isconsumed by this system. Emission of N2O asinfluenced by application of urea, urea plus farm yardmanure (FYM), and urea plus dicyandiamide (DCD), anitrification inhibitor, was studied in rice-wheatsystems of Indo-Gangetic plains of India. Total emissionof N2O-N from the rice-wheat systems varied between654 g ha-1 in unfertilized plots and 1570 g ha-1 in urea fertilized plots. Application of FYM and DCDreduced emission of N2O-N in rice. The magnitude ofreduction was higher with DCD. In wheat also N2O-Nemission was reduced by DCD. FYM applied in rice had noresidual effect on N2O-N emission in wheat. In riceintermittent wetting and drying condition of soilresulted in higher N2O-N emission than that ofsaturated soil condition. Treatments with 5 irrigationsgave higher emissions in wheat than those with 3irrigations. In rice-wheat system, typical of a farmer'sfield in Indo-Gangetic plains, where 240 kg N isgenerally applied through urea, N2O-N emission is1570 g ha-1 (0.38% of applied N) and application ofFYM and DCD reduced it to 1415 and 1096 g ha-1,respectively. 相似文献